Is this flywheel good?

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samaritan

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lagrange ky
I've replaced 3 , what's the best way to check em?coils in my saw this year, I'm wondering if the magnets are good yet on my ms251c
 
Harley if kill switch and wire are eliminated, and known good coils are tried, still no spark. What next?
Real question and not just fishin.
 
I've replaced 3 , what's the best way to check em?coils in my saw this year, I'm wondering if the magnets are good yet on my ms251c

You have replaced the flywheel on one saw three times?
Or in your lifetime of working on saws you have only had to replace three flywheels?
 
The only reason folks need to replace flywheels are when they damage them trying to remove them. I have never experienced the "magnet-loss" thing. I believe it is called a "red-herring".

Those poly wheels on late 066 or 660's can do funny things.
Busted off fins are pretty common in farmer saws I see- escaped bolts falling into the recoil at WOT are usually responsible.
Coil rub can upset magnets........ but for them to just go bad for no real reason- not usual.
 
It helps if you unscrew the plug and ground it to the cylinder so the drill isn't fighting the saw's compression.
That's not testing for anything. A spark tester needs to be hooked up to the high tension lead to properly load the ignition system. Even a 3/4 shot coil will fire a spark plug in open air.
 
That's not testing for anything. A spark tester needs to be hooked up to the high tension lead to properly load the ignition system. Even a 3/4 shot coil will fire a spark plug in open air.
An old farmer trick is to open the plug gap up ~1/4". If the coil jumps that they are usually good.
 
The best ignition tester I have is a non extended tip sparkplug with the side electrode cut off and an alligator clip welded to the side. If it sparks, it will start, unless the flywheel key is sheared.
 
The best ignition tester I have is a non extended tip sparkplug with the side electrode cut off and an alligator clip welded to the side. If it sparks, it will start, unless the flywheel key is sheared.
That style only works on certain ignitions, as evidence of Briggs and Stratton have 4 different versions for different ignition systems. An adjustable gap spark tester is all you will need, cheap and can test any ignition system made.
 

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